I was considering working on a PW replacement but I'm just not terribly interested at the moment because the PW's don't have the features I want.

Instead I want to build a replacement circuit board for the Vivitar 285HV. This board will incorporate digital power selection, optical slaving, and wireless (RF) triggering, as well as the ability to set the power for the flash wirelessly. This will mean building a transmitter as well, but if I can't set the power remotely then I don't see the point in building it at all.

I want this board to cost under $25. I'm shooting for a 500' range with complete reliability using the 344MHz spectrum with FSK. This would give us a kickass flash, brand new, with features no other flash has, all for $125. This would be a flash truly worthy of the Strobist tradition (at least I think so).

I want the board to be installable with a minimum of effort and modification. More than likely this will mean nothing more than drilling holes for several LED's and a couple of buttons.

In the end I want the flash to look as close to stock as possible while having as many useful features as possible.

I'd like suggestions from people for features/requirements. I don't see the point in keeping the stock Vivitar HV jack for example. I'd rather use my own jack and power supply if push comes to shove. I do want to retain the ability to use the internal batteries, and I want the board to use the same batteries. Does anyone else have any suggestions?

Apart from a nice reliable trigger (like the PW) remote power adjustment would be the main feature I'd like for sure.

But I'd definatley want to be able to trigger lights/flashes other than the 285 as well at the same time, so if there was seperate dumb receivers as well that just riggered any flash, and all triggered by the same transmitter that would be great. Otherwise having to choose one direction, I'd likely go with the PW or Skyports etc.

The Sunpak 383 might be another option too? I don't know if theres much room inside either of them though.

You wouldn't want the signal to get flakey though as the flash batteries wore down either though?! The more I think about it I think an external receiver would be preferable but maybe connect it to the new circuit board with power adjustment in the 285 and just as a dumb trigger for other units.

But I'd definatley want to be able to trigger lights/flashes other than the 285 as well at the same time, so if there was seperate dumb receivers as well that just riggered any flash, and all triggered by the same transmitter that would be great.

Definitely. I have 580ex II's I want to trigger using the same wireless signal.

The Sunpak 383 might be another option too? I don't know if theres much room inside either of them though.

I haven't taken apart the 383 so I don't know if there is enough room. Also- the 383 doesn't do zoom does it?

You wouldn't want the signal to get flakey though as the flash batteries wore down either though?!

The NiMH batteries have a nice steady power output and I don't use these for weddings where I need 200+ flashes. For those that want longer life you could simply use the external battery pack.

The more I think about it I think an external receiver would be preferable but maybe connect it to the new circuit board with power adjustment in the 285 and just as a dumb trigger for other units.

That adds to the cost because now you need two boards- one for the 285 and an external receiver- plus the external receiver needs a case- more extra cost.

I'm not ruling out the idea but I think simpler is better- a single tiny, integrade board would mean less to carry- less weight and less bulk, and I prefer compactness when possible.

All of this may be a moot point- it's entirely possible I won't be able to get a clean wireless signal with an internal board and I'll have to go back to an external board.